原著

臨床分離 Extended Spectrum β-lactamases(ESBLs)産生
Escherichia coli由来のTEM遺伝子における
新規塩基置換の検出

安　原　　　努*1　福　地　邦　彦*2
高　木　　　康*3　五　味　邦　英*4
　　　　　　　　　　　　　　　　　　　　　　
Detection of Novel Nucleotide Substitutions Resulting Amino Acid Substitutions
in TEM Type b -Lactamase Gene Isolated from a Clinically Isolated
Extended Spectrum b -Lactamases(ESBLs) Productive Escherichia Coli

Tsutomu YASUHARA, MD*1, Kunihiko FUKUCHI, MD*2,
Yasushi TAKAGI, MD*3 and Kunihide GOMI, MD*4

We screened Escherichia coli (E. coli) from specimens submitted to the Showa University hospital clinical laboratory that showed an advanced resistance to third generation cephems(Cefotaxime or Ceftazidime), as candidate extended spectrum β-lactamases(ESBLs) producing strains. Among the candidates, two strains showed the characteristics of class A ESBLs in their susceptibility to Cefmetazole, a second generation cephem, and their resistance was inhibited by the addition of clavulanic acid. Further, we detected the TEM-type gene in one of the two E. coli strains. By determining the nucleotide sequence of the whole coding region of the TEM gene, two nucleotide substitutions with amino acid substitutions ⁸²Val→Ile, and ¹⁸²Ala→Val were identified.
[Rinsho Byori 51 : 201〜207, 2003]

*1Department of Clinical Pathology, Showa University, School of Medicine, Shinagawa-ku, Tokyo 142-8666

【Key Words】ESBLs(基質拡張型 b ラクタマーゼ)，E. coli (大腸菌)，TEM gene(TEM 遺伝子)，mutation(突然変異)，nucleotide substitution(塩基置換)

受付2002年11月19日・受理2003年2月13日
*1〜4昭和大学医学部臨床病理学教室(〒142-8666 東京都品川区旗の台1-5-8)

E-mail :4k1t0y87@med.showa-u.ac.jp